Watch the transitions. When holding a pose, he can be affable but impenetrable. When moving into the next one, he is at his most intriguing because there is some question about whether he will stick the landing. For a born bodybuilder, the notion of posing has only the best connotation. It is not a pose in the sense of a paralegal with an ankle tattoo or an undergrad in a Che Guevara T-shirt. In bodybuilding, posers win. Pros call it “standing in your shot.” The best never tremble as they flex. And they never forget to smile. The seven Mr. Olympia victories through which Schwarzenegger flashed his gap-toothed grin entailed a compulsory series of poses: front double biceps,front lat spread, back lat spread, front abdominal-side isolation, and so on. The heavy bronze trophy given to the winners of the Arnold Classic, his tournament in Columbus, Ohio, depicts a patented Arnold pose called the “three-quarter back.”

Each pose for Schwarzenegger is a different mode of the same expression. In all, he is Arnold, a familiar pop-culture archetype. The gap in his teeth has disappeared, but the squinting blue eyes, close-cropped brown hair and cigar have not.

The image has gotten a slight 21st-century update. Arnold is now an action star at 55, a survivor of heart surgery and shoulder surgery, a serious motorcycle accident, a disastrous investment in Planet Hollywood and waning fortunes at the box office. Since his last solid hit, “Eraser” in 1996, worldwide grosses have nose-dived — $ 238 million, $ 209 million, $ 116 million, $ 83 million. To a certain schadenfreude-prone segment in Hollywood, the numbers are a countdown to extinction.

Sitting in his vast Santa Monica office three floors up from his restaurant Schatzi on Main, however, Schwarzenegger is returning to a pose that induces pleasant muscle memory: well-paid star of one of Hollywood’s most successful franchises. Schatzi may often sit empty, but Schwarzenegger’s plate is full.

“Terminator 3: Rise of the Machines” will open in July, but the publicity machine is about to hit top gear, with a big splash planned during Cannes. There will be, at a minimum, an MTV-sponsored party at Pierre Cardin’s villa, a separate bash on a yacht, as well as stunts involving Arnold and robots. Foreign rights to the film have already been settled, so Cannes will serve as a massive international press junket.

The film, at $ 170 million the most expensive Hollywood has greenlit, is what studio lot denizens call “locked.” A nearly finished version was screened in April for the top brass at Warner Bros., the domestic distributor, and Sony, which is handling most overseas territories. A sigh of relief blew from Burbank to Culver City and back again.

“The movie looks fantastic,” says the star, sporting trademark khakis and black leather lace-ups. Before continuing, he lights his cigar with a miniature blowtorch. “No, there is another word for it, I think: extraordinary. Fantastic is not the right word. Because with the music and the sound, it’s becoming, like, complete. Spectacular.”

Schwarzenegger reprises his role as the O.G. Terminator model, battling the fearsome T-X (Kristanna Loken). The aim is to save John Connor (Nick Stahl) and his companion, a med student played by Claire Danes. Save them and you save the world from the clutches of the machines.

Like his embattled villain-turned-hero, Schwarzenegger is also fighting an entrenched opposition: industry cynics who consider him the guest who stayed too long at the party. He was amusing at midnight but now it’s 2 a.m. and time forbeddie-bye. A massive (some might say cheesy) Super Bowl push for “T3,” including TV spots and a sideline interview, may have hurt the property, rival studio execs contend.

None of the snipers will go on record, of course. But they are still taking aim, and Schwarzenegger has long fed on their negativity. “One agent said to me, ‘No one who ever did a movie with an accent was successful,'” he says with the same impassive trace of a smile he wears when terminating someone onscreen.

“Someone else said, ‘It’ll never work with this name.’ Other people said, ‘This body is totally off. Why don’t you get out of the business and go make some health food stores?’ But I felt that I could turn all of those obstacles into assets.”

James Cameron, architect of the franchise, fell out of “T3″ soon after producers Andy Vajna and Mario Kassar won the rights in a bidding war. Two months before the release of the megabudgeted “Titanic,” with buzzards circling, Cameron and Fox jointly announced they would not let themselves in for more scrutiny by taking on “T3.” (Cameron, who had secretly been pursuing his own bid for the ‘T3′ rights, reportedly felt betrayed by Vajna and Kassar.) Jonathan Mostow, whose biggest action title to date is the submarine thriller “U-571,” wound up in the director’s chair.

Mostow, a bespectacled 41-year-old with a disarming intellect, met Schwarzenegger at his home in Pacific Palisades and spent two hours in the den laying out his sequel vision. He says he was grateful to be pitching a star who relishes the sales part of filmmaking as much as the acting.

“He had such an intuitive understanding of how the audience understands and enjoys the character. So few actors are able to take a step back and clearly see those considerations.”

Mostow also concedes, “As a movie fan, it was the ultimate experience” working with Schwarzenegger. During the shoot, in fact, he enthused to a reporter: “I feel like I’m making the Bible and I’ve got Moses playing Moses.”

Since September, when shooting wrapped in L.A. on “T3,” Schwarzenegger has been in more of a PR comfort zone. He switched agencies, from William Morris to CAA, and reports began circulating about big-budget sequels to “Conan the Barbarian,” “True Lies” and “Total Recall.” He attended the New York pre-miere for the 25th anniversary of “Pumping Iron,” the doc that first took Schwarzenegger to Cannes and gave him a public profile. Negative headlines about “Collateral Damage” and a nasty takedown attempt by Premiere magazine have since faded away.

And in November, the after-school funding initiative Proposition 49 was approved by California voters by a convincing margin. His stewardship of the campaign fed speculation that the Austrian Oak (as he was dubbed in his bodybuilding days) was poised to run for governor in 2006. He remains coy about his future, saying only that he has not yet committed to start shooting another film.

“Of course I haven’t made a decision, otherwise I’d be out there running,” he shrugs. “Right now, I’m very focused on promoting the movie and on show business” — pronounced “cho business” — “and if I decide to switch over to that other thing, then I would have to make the announcement that I was retiring.”

Though Republican strategists applauded Schwarzenegger for taking on a ballot initiative before trying his hand at a full-fledged campaign, he scoffs at the notion.

“They think that everything you do is calculated,” he says. “When I did Prop. 49 they said, ‘This is his way to get into the political arena.’ When I sold my Ferrari, they said, ‘Oh, he’s getting rid of his European car.’ If you run, you run. Ronald Reagan didn’t have any proposition and he ran. Bill Bradley never had a proposition. He came from basketball and ran for Senate.”

One difference between Schwarzenegger and any other political predecessor is that he would enter the campaign fresh from a $ 30 million role in a worldwide event film. If “T3″ becomes a hit, it could serve as the ultimate launch pad. Imagine the news conference — “Yes, I am going to run, and pick up a copy today of the new ‘T3′ DVD!” It’s a crossover his “Predator” co-star Jesse Ventura could only dream of.

For now, Schwarzenegger is demure (or as demure as a 6-foot-2-inch,220-pound action star can be) when asked directly about politics. He has characterized his orientation as fiscally conservative but “very liberal” on social issues; he backs abortion rights, adoption by gay parents and, yes, an assault weapons ban. In conversation, his answers to nonpolitical questions often morph into stump speeches. For example, discussion of Cannes prompts a diatribe about the boycott of the 1980 Moscow Olympics (“the biggest bunch of garbage I’ve ever seen … we boycotted instead of finding a military solution”).

Then, of course, there’s that bust of Lenin.

Schwarzenegger’s sprawling office within his company, Oak Prods., contains busts of Lenin, Reagan and John F. Kennedy (whom Schwarzenegger admired, he says, even before marrying Maria Shriver, JFK’s niece). A group of body-builders from St. Petersburg brought the 3-foot Lenin head into the U.S. after the Soviet Union dissolved and presented it to Schwarzenegger. The next year, they wanted to top themselves.

“When they unveiled (a bust of) Stalin, I said no. I had to explain to them why,” he says. “Lenin was not as evil. He was just in the right place at the right time. But Stalin was evil. He was a dictator beyond belief. There were questions of who was more evil, Hitler or him.”

For the record, there are no plans for a Saddam Hussein statue in the Oak offices. “Saddam didn’t start anything great,” he says. “But Lenin started communism and the whole Karl Marx thing. He started something that lasted 70-something years.”

Beyond the busts, Schwarzenegger’s office could itself be the subject of a VLife profile. It’s so big that the Lakers could play full-court while he read scripts and he would barely notice. The decor blends beachfront sandstone tones with the trappings of a red meat-eating clubroom. Gas-fed flames illuminate a white marble fireplace, the mantle of which is crammed with framed photos of Schwarzenegger with dignitaries like Mikhail Gorbachev and Bill Clinton. The largest photo, at the center, is a black-and-white of his parents, Gustav and Aurelia.

The walls are fully occupied. One has a Warhol. There’s an illuminated oil painting of an oiled-up Schwarzenegger striking a pose. Another wall holds an array of intermingled trophies, from a Golden Globe for best film newcomer for his role in Bob Rafelson’s film “Stay Hungry” to awards from ShoWest made of Lucite. A waist-high statue of Eugen Sandow, father of bodybuilding, stands guard at the entrance, near 8-foot replicas of Terminator robots and the beast from “Predator.”

It doesn’t take much prodding for Schwarzenegger to conduct a tour of the impressive space. He holds his cigar like a flashlight, careful not to spill ashes on the industrial carpet. He chuckles at the memories each piece of memorabilia inspires, as if for the first time. He doesn’t exactly dwell on Memory Lane, but neither he does he need directions to get there. It’s a paradox of Arnold: He is hardly Madonna-like in his ability to reinvent himself, but few can match his batting average over the past two decades. Mostow marvels that “he has outlasted them all. You have to go back to John Wayne to find that kind of consistency.” “T3″ represents a bet on straight-ahead action, a concept its star embodies.

Assessing the competition, Schwarzenegger takes a few seconds to conjure the title “The Matrix,” and then immediately draws a boundary between his fisticuffs-and-bullets approach and digital effects-saturated tentpoles. With the likes of Keanu Reeves, Tobey Maguire and Elijah Wood leading a new Everyman action movement, it is clear that Schwarzenegger wants to stake a more traditional claim.

“At the time, ‘Terminator 2′ was groundbreaking. But there hasn’t really been that much done since then,” he contends. Effects “have been used more. But the things that we’re seeing — like ‘Lord of the Rings’ and other movies, like ‘Jurassic Park’ — have some groundbreaking things. It gives you a chance to make people feel like they’re part of the story because you don’t have to cut away all the time.”

This orthodoxy is nothing new. When “T2″ was released, Cameron sized up his leading man this way: “He’s never gonna play a character where he sits around in an office and wrings his hands. He is about direct action. He’s about being decisive. He’s about knowing what you want and going for it. He’s very clear.”

Nietzschean clarity did not always serve him — especially in the auteur 1970s, when the current action-sequel industry did not even exist. Pausing by the Sandow statue, he recalls the years in the ’70s when he was billed onscreen as Arnold Strong in films like “The Long Goodbye” and the struggle to move from gym to screen.

“Bodybuilding got me to America. When I saw my idols — Steve Reeves, Kirk Douglas, Charlton Heston, John Wayne — all those guys were these very heroic guys,” he says. “But what fascinated me the most about guys like Steve Reeves was that they won Mr. Universe first and then got into movies. They never really trained to get into movies. They trained as bodybuilders. I was thinking the only way I would ever get to America or get into movies was that route. So I, like a fanatic, started training. Then, after I won all of those champion-ships and came to Hollywood, people said I was 25 years behind the times.

“There were still guys like Clint Eastwood and Charles Bronson, but the guys who were really cutting edge were Dustin Hoffman, Warren Beatty, Jack Nicholson. I had to expand my dream. I was programmed to be a star.”

This Dale Carnegie-meets-Jack La Lanne mentality means a big bet on old-school action. Even though action-hero contemporaries like Sylvester Stallone and Bruce Willis have fallen off, Schwarzenegger is not planning any major gear shifts, not even another comedy in the vein of “Twins” or “Kindergarten Cop.” For better or worse, he’s staying in his pose, not a tremble in sight.

“In general, any action movie made well does as well today or better than it did 10 or 20 years ago. I remember when I saw this movie ‘XXX.’ It made over $100 million and it made that amount because it was exciting, it was fun, my kids loved it. People thought it was good entertainment. It was a new way of making action movies. Great visual effects, great imagination. Making it cool with the music. You just have to stay with the time, stay with the technology.”

Even if every element is in place — cool music, dazzling effects, good director, beloved characters, tight script — one enemy lies in wait: time.

Even if he forgoes politics and resists the temptation to augment his real estate empire, he will not be able to reprise the same roles forever. Advanced age is an action star’s most trying pose.

Schwarzenegger adamantly keeps those thoughts at bay, but he is honest about his 11-month recovery from surgery to repair a left shoulder worn down by stunts on “T3.” For the cyborg who once tossed off lines like “I’m a cybernetic organism, living tissue over a metal endoskeleton,” the experience has been eye-opening.

“I’m going through physical therapy,” Schwarzenegger says. “It’s tedious,painful and long. The doctor told me, ‘This will be four times as painful as your heart surgery.’ And it was. With my heart surgery, a week later I was home, another week later, I was hiking up in Will Rogers Park with my dogs. But this is, like, unbelievable the amount of time it takes.

“There are strange exercises that you never thought you couldn’t do. You feel totally crippled. Just lying in bed on your stomach and raising this arm up. You have no strength and if (the therapist) puts the finger on, you can’t do it. For a guy who has lifted so much and when you’ve been in shape and could do a lot of things, it’s a really wild thing. The only thing you can think of is, ‘I’m going to come back much better than what I was.'”